Statistics: Testing Hypotheses

The attached file contains the yield for a money market account, a one-year certificate of deposit (CD), and a five-year CD for 23 banks.
a) At the 0.05 level of significance, is there evidence of a difference in the mean yield of the different accounts?
b) If appropriate, determine which accounts differ in mean yields.
c) At the 0.05 level of significance, is there evidence of a difference in the variation in yields among the different accounts?
d) At the 0.05 level of significance, is there evidence of a difference in the median yields of the different account?
e) Compare the results of (a) with (d).